Receptacle device for the rotor assembly of a turbocharger

ABSTRACT

A turbocharger has a turbocharger housing with at least one section that is divided in the longitudinal direction into at least two housing halves. A receiving device for receiving a rotor assembly of the turbocharger can be fastened to at least one half of the housing.

The invention relates to a receptacle device for the rotor assembly of a turbocharger, wherein the rotor assembly comprises a shaft, a bearing arrangement and at least one rotor wheel, and wherein the housing of the turbocharger is designed so as to be divided in the longitudinal direction into at least two housing halves.

In general, a turbocharger comprises an exhaust gas turbine in an exhaust gas mass flow, which is connected by a shaft to a compressor in the intake section. The turbine wheel of the turbine is arranged in a turbine housing, and the compressor wheel of the compressor is arranged in a compressor housing. The shaft, in turn, is supported in a bearing housing. During operation, the turbine wheel is driven by the exhaust gas mass flow and, in turn, drives the compressor wheel. The compressor compresses the induced air and feeds it to the internal combustion engine. Normally, the shaft is supported in the bearing housing by means of a radial bearing arrangement. Owing to fluid flows acting on the turbine wheel and the compressor wheel, powerful axial forces can occur. The radial bearings are generally not suitable for absorbing such axial forces. The usual practice is therefore to provide at least one or two additional axial bearings in order to absorb these axial forces in an appropriate manner.

The existing design of turbochargers furthermore provides for individual housings which are fastened one behind the other and sealed off relative to one another. A new form of turbocharger housing now envisages dividing the turbocharger housing in the longitudinal direction, not transversely to the longitudinal axis thereof as hitherto.

This new turbocharger housing is the subject matter of a separate patent application.

Thus, it is the object of the present invention to provide an improved receptacle device for a rotor assembly of a turbocharger, wherein the turbocharger has a turbocharger housing divided in the longitudinal direction into at least two housing halves.

This object is achieved by a turbocharger having a receptacle device with the features of patent claim 1.

Accordingly, the invention provides a turbocharger having a turbocharger housing, wherein at least one section of the turbocharger housing is designed so as to be divided in the longitudinal direction into at least two housing halves, wherein a receptacle device for receiving a rotor assembly of the turbocharger is provided.

The turbocharger has the advantage that the receptacle device can be fully preassembled with the rotor assembly, i.e. the shaft and the bearing assembly thereof plus the rotor wheels, and then inserted into the housing halves. The receptacle device, together with the rotor assembly in addition, can then be fastened to one or both housing halves. In the case of the existing turbocharger housings, which were of closed design, the rotor assembly had to be, as it were, slipped on, there being no possibility of preassembly.

Advantageous embodiments and developments of the invention will emerge from the dependent claims and from the description with reference to the drawings.

The invention is explained in greater detail below with reference to the embodiments indicated in the schematic figures of the drawings, in which:

FIG. 1 shows a sectioned view of a turbocharger, wherein the turbocharger housing is divided in the longitudinal direction into two housing halves, wherein the turbocharger has a receptacle device according to a first embodiment of the invention;

FIG. 2 shows a further sectioned view through a turbocharger housing having a receptacle device according to a variant of the first embodiment of the invention;

FIG. 3 shows a sectioned view through a turbocharger housing having a receptacle device according to a second embodiment of the invention; and

FIG. 4 shows a sectioned view through a turbocharger housing having a receptacle device according to a third embodiment of the invention.

In all the figures, elements and apparatus which are the same or have the same function have been provided with the same reference signs, unless otherwise indicated. Moreover, the depiction of the turbocharger in the following figures is shown in a purely schematic way, which is not to scale and is greatly simplified.

For assembly, an appropriate design of turbocharger housing is one in which at least one section of the turbocharger housing is designed so as to be divided in the longitudinal direction into at least two housing halves, thus enabling the rotor assembly to be inserted radially. Hitherto, the rotor assembly was installed axially in a bearing housing, and the components of the rotor were, as it were, slipped on. In this case, the housing is normally of closed design.

According to the invention, the rotor assembly of a turbocharger and the bearing assembly thereof is received in a turbocharger housing divided in the longitudinal direction into at least two housing halves, as shown by way of example in following FIGS. 1 to 4. In the process, the rotor assembly is preferably positioned with respect to the contour of the flow-guiding surfaces. In this arrangement, the turbocharger housing or at least one housing half can be designed so as to be integrated at least partially or substantially completely into an engine block of a connected internal combustion engine and/or into a corresponding cylinder head or cylinder heads of the internal combustion engine.

Moreover, a seat is formed for a respective sealing device in such a way that it has a certain concentricity so as to be leaktight and maintains a certain predetermined play.

FIG. 1 first of all shows a sectioned view through a turbocharger 10 having a turbocharger housing 12, which is embodied in such a way as to be divided in the longitudinal direction, into at least two housing halves 14, 16 for example. In the example in FIG. 1, the turbocharger housing 12 has a bearing housing 18, a turbine housing 20 and a compressor housing 22, and, by way of example, all three housings are combined into a single housing and designed so as to be divided in the longitudinal direction into two housing halves 14, 16. In the present case, the turbocharger housing 12 is embodied in such a way as to be divided in the longitudinal direction, in a horizontal plane for example, wherein the longitudinal axis 24 of the turbocharger housing 12 lies in the horizontal plane. In principle, however, the turbocharger housing 12 can be designed so as to be divided in the longitudinal direction into at least two housing halves 14, 16 in any plane. Moreover, the longitudinal axis 24 does not have to lie in this parting plane or intersect the latter, for example, although it can do so, in principle.

In the present example, the turbocharger housing 12 is, as an option, additionally embodied in such a way that it can be at least partially temperature-controlled or cooled and/or heated. To be more precise, the region of the turbocharger housing 12 in the example shown in FIG. 1, e.g. the rotor wheel housing 20, 22 and/or the bearing housing 18, has an additional fluid jacket 26, in which a fluid, e.g. water, can be circulated in order to cool and/or heat this region of the turbocharger housing 12, depending on function and application.

The housing halves 14, 16 shown in FIG. 1 are fastened to one another and sealed off from one another. For this purpose, a plurality of holes, for example, for screwing the two housing halves 14, 16 to one another are provided (not shown). Moreover, it is also possible to provide any other form of fastening which is suitable for connecting the two housing halves 14, 16 to one another and allowing or itself providing a seal between the two housing halves 14, 16. For the purpose of sealing the two housing halves 14, 16, it is possible, for example, to provide a sealing device 28 which has, for example, at least one beaded seal, O-ring seal and/or elastomer seal. The seal, e.g. the beaded seal, is inserted into a corresponding seal seat in one housing half 14, 16, e.g. into a corresponding recess or groove. It is likewise possible, for example, simply to insert the beaded seal directly between the two housing halves 14, 16, with the other, unsealed, housing half surfaces preferably being in direct contact. The sealing of the two housing halves 14, 16 forms the subject matter of a separate patent application.

In FIG. 1, a shaft 30, on which a turbine wheel 32 and a compressor wheel 34 are provided as rotors, is supported in the bearing housing section 18 of the turbocharger housing 12. The turbine wheel 32 is arranged in the turbine housing section 20, and the compressor wheel 34 is arranged in the compressor housing section 22 of the turbocharger housing 12.

A first embodiment according to the invention, as shown in FIG. 1, provides a sleeve element or inserted sleeve 36 as a receptacle device, said sleeve being inserted, together with the installed rotor, i.e. the shaft 30, a bearing assembly, the compressor wheel 34 and turbine wheel 32, into the housing halves 14, 16 of the divided turbocharger housing, and optionally being additionally fastened therein by means of one or more pin elements and/or screws, for example, and therefore secured. The sleeve element or inserted sleeve 36 according to the first embodiment of the invention has the advantage that it can be inserted together with the fully assembled rotor assembly into the housing halves 14, 16 of the longitudinally divided turbocharger housing 12 or, for example, can be inserted into corresponding cylinder head halves (not shown) and/or the engine block, into which one or both housing halves can be designed to be at least partially integrated.

Moreover, it is possible, as an option, for an axial bearing arrangement or at least one axial bearing to be additionally fastened to the inserted sleeve 36, as shown by way of example in following FIG. 2. This has the advantage that the oil flow and the bearing tolerances can be implemented in an optimum manner and that the position of the bearing arrangement and of the oil feed relative to one another can be better defined.

In the example shown in FIG. 1, a radial bearing arrangement 38 is provided in the inserted sleeve 36 to provide support for the shaft 30 in the radial direction. In this case, the radial bearing arrangement 38 has two radial plain bearings 40, for example. However, any other type of radial bearings can be provided, e.g. magnetic bearings, rolling contact bearings etc. In FIG. 1, the radial plain bearings 40 are arranged in the inserted sleeve 36, being spaced apart by a spacer sleeve 42, for example. In principle, any other radial bearing arrangement can be arranged in the inserted sleeve 36. Moreover, it is also possible, in place of a spacer sleeve 42, to design the inserted sleeve 36 internally as a spacer sleeve for the two radial plain bearings, as shown in following FIG. 2. The present invention is not restricted to the specific example of a radial bearing arrangement in FIG. 1.

As shown in FIG. 1, the inserted sleeve 36 optionally has, in addition, at least one lubricant feed 44 for lubricant for at least one or both bearings or, in this case, plain bearings of the radial bearing arrangement, wherein lubricant feed 44 is connected to the lubricant feed 46 of the turbocharger housing 12.

As shown in FIG. 1, the inserted sleeve 36 is inserted with the shaft 30 and at least one or both rotor wheels 32, 34 into the respective housing half 14, 16 of the turbocharger housing 12.

The shaft 30 forms an offset with a stop for the radial bearing arrangement 38, for example. As an option, an axial bearing arrangement 48 is additionally provided at the other end of the inserted sleeve 36, having at least one axial bearing 50, wherein the axial bearing 50 is designed as an axial bearing washer, for example, and can be additionally fastened to the inserted sleeve 36, depending on function and application, as shown by way of example and in a purely schematic way in following FIG. 2. For this purpose, the axial bearing can be fastened to the inserted sleeve 36 by means of screwing and/or pinning, for example, depending on requirements. As an alternative, it is also possible for the axial bearing 50 and the inserted sleeve 36 to be fastened jointly to the turbocharger housing 12, e.g. by means of screwing and/or pinning (not shown).

As an option, the axial bearing 50 can additionally be bounded on one side by a bush element 52, for example. The bush element 52 can additionally have at least one sealing device 54 on the outside thereof for the purpose of sealing the bearing housing section 18, for example, with respect to the rotor wheel housing section 22. Two piston ring seals in corresponding grooves on the outside of the bush element 52 can be provided as a sealing device 54, for example. As described above, it is possible, according to the first embodiment according to the invention, for the inserted sleeve 36 to be preinstalled directly on the shaft 30 and then to be inserted with the rotor assembly into the respective housing half 14, 16 of the turbocharger housing 12.

FIG. 2 shows another sectioned view of a turbocharger housing 12 divided in the longitudinal direction into at least two housing halves 14, 16, wherein a sleeve element or inserted sleeve 36 according to the first embodiment of the invention is likewise used as a receptacle device.

Here, a radial bearing arrangement 38 is received in the inserted sleeve 36 in order to provide support for the shaft 30 in the radial direction. The radial bearing arrangement 38 likewise has two radial plain bearings 40, for example, wherein the inserted sleeve 36 is simultaneously designed as a spacer sleeve for the purpose of positioning the two bearings. An additional lubricant feed 44 leading to one or both radial plain bearings 40 can furthermore be provided in the inserted sleeve 36, said lubricant feed being connected to a corresponding lubricant feed 46 of the turbocharger housing 12 and/or one housing half 14. As an option, an axial bearing arrangement 48 can also additionally be provided as well as the radial bearing arrangement 38, said axial bearing arrangement having at least one axial bearing 50 for example, e.g. in the form of an axial bearing washer. The axial bearing 50 in FIG. 2 is shown in a greatly simplified form and in a purely schematic way. As indicated in FIG. 2, at least one axial bearing 50 can, for example, be additionally fastened to the inserted sleeve 36, e.g. by means of screwing and/or pinning. For this purpose, the axial bearing 50 is fastened to a collar section 56 of the inserted sleeve 36, for example. In principle, the inserted sleeve 36 can have a collar section 56 of this kind at one or both ends, wherein the collar section 56 can be of elastic/flexible or rigid design. In the case of at least one elastic or flexible collar section 56, the inserted sleeve 36 can thus be clamped in a receptacle 58 of the turbocharger housing 12. However, it is likewise possible for the collar sections 56 to be omitted. In this case, it is likewise possible for the axial bearing 50 to be additionally fastened directly to the turbocharger housing 12 by screwing and/or pinning.

The inserted sleeve 36 has the advantage that it can be inserted into the housing halves 14, 16 of the turbocharger housing 12 or, for example, into a cylinder head or into an engine block (not shown), together with the fully assembled rotor assembly, in which case a screwing operation can be omitted. In addition, damping of the oil or lubricant surrounding the sleeve is obtained.

FIG. 3 furthermore shows a sectioned view through a turbocharger housing 12 having a bearing bracket 60 as a receptacle device for supporting the rotor assembly of the turbocharger 10 according to a second embodiment of the invention.

This shows a bearing bracket 60 which has in each case at least one lug 62 or projection on one or both sides for fastening to the turbocharger housing 12. The bearing bracket 60 is fastened to one housing half 14 of the longitudinally divided turbocharger housing 12, e.g. by means of screwing and/or pinning. In the example in FIG. 3, the bearing bracket 60 is fastened to the housing half 14, 16 by screws 64, for example. The shaft 30 of the turbocharger 10 is received with a bearing arrangement, in this case a radial bearing arrangement 38 for example, between the bearing bracket 60 and the housing half 14, 16 of the turbocharger housing, as is shown in greater detail in FIG. 3. The radial bearing arrangement 38 has two radial bearings in the form of radial plain bearings 40, for example. At least one or both radial bearings 40 of the radial bearing arrangement 38 are received by the bearing bracket 60. As an alternative, it is also possible for each radial bearing to be received in a dedicated bearing bracket 60.

After the insertion of the shaft 30 with the two rotor wheels 32, 34 and the radial bearing arrangement 38 and/or axial bearing arrangement 48 into a housing half 14 of the turbocharger 10 for example, the respective bearing bracket 60 is attached to said housing half 14 in order to fasten the rotor assembly additionally thereon.

The bearing bracket 60 and, with the latter, the rotor assembly is fastened to the housing half 14 by means of screwing or pinning, for example, as described above. By providing the bearing bracket 60, preferably together with the turbocharger housing 12 or the associated housing half 14, with a pinned or screwed joint or machining it in an appropriate manner, a bearing receptacle for the respective bearing arrangement is obtained which has a high truth of running and accuracy of position, even after reassembly. Another advantage of this embodiment is that there are no interruptions in the bearing surfaces due to a seal, which would otherwise disrupt the sliding film of a plain bearing arrangement, for example. This also enables the lubricant discharge to be configured in an optimum manner.

FIG. 4 shows a sectioned view through another turbocharger housing 12 divided in the longitudinal direction into at least two housing halves 14, 16. According to the third embodiment of the invention, a bearing core or bearing block 66 is used as a receptacle device for mounting the rotor assembly of the turbocharger 10.

As shown in FIG. 4, the bearing core or bearing block 66 is fastened in one of the housing halves 14 of the longitudinally divided turbocharger housing 12, together with the assembled rotor assembly. As an alternative, it is also possible for the bearing core 66 to be fastened, e.g. screwed, into a cylinder head and/or an engine block for example, into which at least one housing half can be at least partially integrated for example.

In the example shown in FIG. 4, the bearing core 66 has an opening 68, in which the shaft 30 of the turbocharger 10 and, for example, a bearing arrangement can be received. The bearing arrangement is, for example, a radial bearing arrangement 38 which has two radial bearings 40, wherein at least one or both radial bearings can be accommodated in the opening 68 of the bearing core 66 with the shaft 30. The bearing core or bearing block 66 is fastened with the shaft 30 and the bearing arrangement to a housing half 14 of the turbocharger housing 12. For this purpose, the housing half 14 has a corresponding receptacle 70 or depression, in which the bearing core 66 is received. The bearing core 66 furthermore has at least one lug 62 on one or both sides, by means of which the bearing core 66 is fastened to the housing half 14, e.g. by means of screwing and/or pinning. In the example shown in FIG. 4, the bearing core 66 is screwed firmly to the housing half 14 on each side by means of its lugs 62 or projections, using screws 64. As a result, the rotor assembly can be inserted into the housing half 14 and fastened thereto very easily with the bearing core 66. The shaft 30 with the radial bearing arrangement 38 with a bearing core 66 or, alternatively, a plurality of bearing cores can be fastened to the housing half 14, wherein each bearing core 66 receives at least one bearing, for example, in this case a radial plain bearing 40 for example.

This embodiment according to the invention has the advantage that the machining for the respective bearing receptacle has to be carried out in only one component, in this case the bearing core 66, since there is no division of the bearing location in this case. This furthermore has the advantage that no offset can arise. Another advantage of the bearing core 66 is that high truth of running can be achieved. Moreover, machining of the bearing location independently of the housing halves 14 in the case of the solution involving the bearing core 66 is advantageous.

The invention as described above by way of example with reference to FIGS. 1 to 4 can furthermore have an axial bearing arrangement, as shown in FIGS. 1 and 2. The axial bearing arrangement has at least one axial bearing, e.g. in the form of an axial bearing washer, wherein the axial bearing can be provided on or additionally fastened to the bearing block or the bearing core, the bearing bracket, the inserted sleeve and/or the housing half of the turbocharger housing. This has the advantage that the axial bearing arrangement can be assembled outside the housing halves and then inserted together with the rotor into the housing halves.

The above-described embodiments relating to the installation of the rotor assembly in a turbocharger housing have the advantage that it is possible to machine the housing halves, the cylinder head halves or the engine block independently of one another. Moreover, as an option, it is possible additionally to provide or additionally to fasten an axial bearing on or to the bearing bracket, the bearing core and the inserted sleeve, making it possible to implement the feeding of lubricant and the bearing tolerances in an optimum manner and to better define the positions thereof relative to one another.

The invention is not restricted to the embodiments described above. In particular, the embodiments described above can be combined, especially individual features of the various embodiments.

The depiction of the turbocharger in FIG. 1 with the support for the shaft and elements thereof, such as the bush element and the bearing arrangements etc. is purely illustrative. The invention is not restricted to this specific embodiment as shown in FIG. 1 and also in the other figures, FIGS. 2 to 4. 

1-10. (canceled)
 11. A turbocharger. comprising: a turbocharger housing, said turbocharger housing having at least one section divided in a longitudinal direction to form at least two housing halves; a receptacle device for receiving a rotor assembly of the turbocharger, said receptacle device being configured for fastening to at least one of said at least two housing halves.
 12. The turbocharger according to claim 11, wherein said receptacle device includes at least one inserted sleeve configured to receive at least a shaft of the rotor assembly and at least one bearing of a bearing assembly.
 13. The turbocharger according to claim 12, wherein said inserted sleeve is configured to receive a radial bearing assembly.
 14. The turbocharger according to claim 13, wherein said inserted sleeve includes at least one lubricant feed for one or both bearings of said radial bearing assembly.
 15. The turbocharger according to claim 14, wherein said turbocharger housing is formed with a lubricant feed and said lubricant feed of said inserted sleeve is connectible to said lubricant fee of said turbocharger housing.
 16. The turbocharger according to claim 12, wherein said inserted sleeve has a collar section at one end or at both ends, and wherein at least one said collar section is elastically flexible.
 17. The turbocharger according to claim 12, wherein said inserted sleeve has a collar section at one end or at both ends, and wherein at least one said collar section is rigid.
 18. The turbocharger according to claim 12, wherein said inserted sleeve is fastenable in said housing halves.
 19. The turbocharger according to claim 18, wherein said inserted sleeve is fastened in said housing halves by screwing and/or pinning.
 20. The turbocharger according to claim 11, wherein said receptacle device includes at least one bearing bracket for receiving at least the shaft and at least one bearing of a bearing assembly.
 21. The turbocharger according to claim 20, wherein said bearing assembly is a radial bearing assembly.
 22. The turbocharger according to claim 20, wherein said bearing bracket has at least one lug or projection on one or both sides thereof for fastening said bearing bracket to a housing half of said turbocharger housing.
 23. The turbocharger according to claim 22, wherein said bearing bracket is connected to said housing half of said turbocharger housing by screwing and/or pinning.
 24. The turbocharger according to claim 11, wherein said receptacle device includes at least one bearing core or bearing block for receiving at least the shaft and at least one bearing of a bearing assembly.
 25. The turbocharger according to claim 11, wherein the bearing assembly to be received by said at least one bearing core or bearing block is a radial bearing assembly.
 26. The turbocharger according to claim 25, wherein said bearing core has at least one lug or projection on one or both sides thereof for fastening said bearing core to a housing half of said turbocharger housing.
 27. The turbocharger according to claim 26, wherein said bearing core is attached to the housing half of said turbocharger housing by screwing and/or pinning.
 28. The turbocharger according to claim 11, wherein said receptacle device is configured for attaching at least one axial bearing of an axial bearing assembly.
 29. The turbocharger according to claim 28, wherein said at least one axial bearing of said axial bearing assembly is fastened to an inserted sleeve, a bearing block, a bearing core, and/or at least one of said housing halves of said turbocharger housing.
 30. The turbocharger according to claim 29, wherein said at least one axial bearing is attached by screwing and/or pinning. 